ppt of memristor

1. MEMRISTOR
PRESENTED BY
E DHANASEKHAR
( 4th YEAR ECE)
(THE FOURTH FUDAMENTAL PASSIVE ELEMENT)

2. Four Fundamental Passive Elements
RESISTOR CAPACITOR
INDUCTOR
?..

3. Symbol -
Unit – ohms (Ω)

4. Definition of Memristor
 A memristor is a semiconductor whose
resistance varies as a function of flux and
current. This allows it to “remember” what
has passed through the circuit.
 Characterized by Memristance
M(q)=dФm
/dt

5. •Theory was developed in 1971 by
Professor Leon Chau at university
of California , Berkeley.
•Found while exploring symmetry
between the three fundamental passive
linear circuit elements
•In 2008, R.Stanley Williams
developed the practical model
Emergence of memristic theory
Prof. LEON.O.CHAU

6. Symmetry Relationship
VOLTAGE
(V)
CURRENT
( i )
CHARGE
( q )
FLUX
(Ф )
Resistor
Inductor
Memristor
Capacitor
V=R i
q=CV
Ф = 𝑴𝒒
Ф= L i
V=dФ/dt i=dq/dt

7. Working
Pt Pt
. . . .
. . . .
TiO2-x
. . .
. . .

8. Working cont...
• Like silicon, titanium dioxide (TiO2)
is a semiconductor , and in its pure
state its highly resistive.
• However it can be doped with other
elements to make it very conductive.
• In TiO2 , the dopants don’t stay
stationary in a high electric field, they
tend to drift in the direction of the
current.

9. Cont…
 Putting a bias voltage across a thin film of TiO2
semiconductor that has dopant on the one side
cause them to move into the pure TiO2 on the
other side. And thus lowers the resistance
 Running current in the other direction will then
push the dopants back into place, increasing the
TiO2’s resistance.

10. ANALOGY OF MEMRISTOR
A Resistor with memory behaves like a pipe
•The diameter of pipe remains same when the current is
switched off, until it is switched on again.
•The pipe , when the current is switched on again ,
remembers what current has flowed through it.

11. V-I Characteristics

12. Advantages
 Hard Disk + RAM =MEMRISTOR
 Eliminates delay
 Speed is inversely proportional to size
 Large density 1 terabit/cm
 Analog data storage possible
 Act as microprocessor
 Non volatile memory
 Uses less energy
 Compatible with current CMOS interfaces
 Faster than flash memory
 Conventional devices use only 0 and 1 ; memristor
can use anything between 0 and 1.
2

13. Applications
 Artificial intelligence
 Cross bar latches as transistor
replacements
 Analog computations
 Circuits which mimic
Neuromorphic and biological
systems(learning circuits)
 Programmable logic and
signal processing

14. Summing it up…..
Thememristorwillenhancecircuit
designinthe21st centuryasradicallyas
thetransistor changed itinthe20th .
 It is believe that it could replace DRAMs
by 2014 and maybe Hard Disk by 2016.

16. THANK YOU